Any ideas that will help my mechanic quickly find the cause of this misfire. Started a few weeks ago that at about 9,000 rpm bike would seem to cut on to one cylinder. Now when cold it will cut out at 5,000 RPM, when warm if I run for about 15 seconds at 6,000 RPM and twist the throttle a little more seems to drop a cylinder but then if you give it full throttle it will mostly accelerate normally till it gets to about 9,000 then it cuts out again. I was thinking blocked fuel filter after searching this site but why would it accelerate normally sometimes on full throttle, at other times full throttle makes no difference. If accelerating full throttle from idle it will sometimes go to the rev limiter without missing at all. It also has a very spasmodic miss at idle, at some red light it will cough 3 times the next time it wont miss at all. The bike is a k8 650 with 50,000 kms on it. Valve clearances recently checked as I was worried the sound I was hearing initially at 9,000 RPM was a valve not closing fully, one exhaust valve was tight and needed re shimming, all 4 spark plugs and air filter replaced at the same time, I will not be working on the bike, thanks for you ideas. One guy on this site had a very similar problem but the answer wasn’t posted. I sent a PM to him but his posts are 2 years old, thanks for your thoughts.